Boiler



Oct. 12, 1943. sc EF I 2,331,508

BOILER Filed Nov. 19, 1941 3 Sheets-Sheet '1 Oct. 12, 1943. H. s. SCHAEFER BOILER Filed Nov. 1.9, 1941 3 Sheets-Sheet 2 Oct. 12, 1943. H. G. SCIHAEFY'ER 2,331,508

BOILER Filed NOV. 19, 1941 5 Sheets-Sheet 3 W I a Patented Oct. 12, 1 943 g 'U l E'EDSTATE-S m O B. Henry G. SchaeferQ Yonkers, N. i

Application November 19,1341', Serial 'No.41 $l,f7 59 than the conven- (Cl. 12 2 234);l g V e "halves S and l'iLfrespectively. "The spherical 'vention to provide a boiler"constructio'n which takesup little room and-is equally adaptable for "industrial and domestic purposes of all kinds,

and which may be builtstron'g and durable from relatively simple p-artsland ata low cost.

Before explaining in detailthe present'invention it [is to be understood that the invention'is inottlimited in its application to the details of construction and arrangement of parts ,illus-' ,trated in the accompanying drawings, '3 since the ji'nventi'on"is capable of other embodiriients and of being practiced or carried out in various ways. Also it i to beunder'stoodftha't the. phraseology or terminology employed herein is for the"pur-.

fbjoiler i4. is provided with a cylindrical down- 'wardextension 32whoseilower endflisgconntd 1thaT-1piece 34"which provides communication betweenjsaidboiler' extension 32 and a water feed 1ine"36'1as Well as a waste line 36, respectively. Communicating with the steam-chamber T40 in theboiler' 14 above the Water level 4 l -therein is a steam conduit '42 through which the steam passes to its place of application. f l

Substantially surroundingflthe boiler m is the furnace ,l2' which comprises aheat conductorjin f for-in of ashellf l' l of any suitablerefractory'niaterial which provides a spiralpassageiw about the boiler 1'4. '1 The upper endiof the spiral pa'ssage 46 communicates with .any suitablelfiue passage.

4a. Projecting at'Suthrou'gh the refractory shell 441and intothe'lowermos't portion of thespir'al passage l5 therein is the nozzle end 52 'ofany 2O conventional combustion burner 34 which jis housed in alateral extensionj56of an outerca'spose of description .and'not oilimitatidn, and it is. not intended to limit the invention claimed herein beyond the requirements of the 'priorart. In'the drawings: t Fig.l 1is a vertical section through a steam generator. embodying the present invention. 1mg. 2 is a horizontal section taken substantially, on the line 2+2 of Fig.1.

I Fig. '13 is an enlarged fragmentary section.

. through the 'wall of the boiler in the present Steam generator.

I'Figs'. 4 and 4a arefsections similar to Fig. 3 and show modified wall constructions of the boiler. H I

Fig. 5 is a vertical section'throug'h a hotwater heater which also embodies the present invention.

- Rotatably ut s in theflboiler in s'lli 15335 v v vReferring to the drawings andparticularly to 'Fig; 1 thereof, the reference numeral lfi desigfnates a steam generator -which comprises a furnace l2 andv a boiler liof'any suitable metal. The boiler M is sphericalin shape and preferably. consists of .two halves l8 and I8 whose abutting surfaces 'and'22, respectively, are preferably ingEBlisee. also Eig-.' 2) 'and may use oilfor fuel. The outer casing 5%, which is preferably or sheet I ;metal,' surroundsfthe shell 4.5 and is open 'at'the t'o'p as at Sfiffor admission .of "atmospheric ".air to the burner "54 for combustion purposes. 'ffIhe airin theouter casing-53in not only preheated for combustionpurposes by the shell .44; but. also effectively heat-insulates said outerflcasingf, from W said shell. The nozzle end 52m theburner"54 is furthermore so disposed (Eig. 12). that the flame 62 is directed substantially. tangentially .of ';-the spiral passage 36 "so as to cause the' .products of combustionto progress through said? spiral pas,- sage with the least obstruction and to. comelinto eiTectiveheat-exchange relation withthe'more" I remote portions of the boiler l l'beforesaidproducts give up most oijtheir heat.

ibearings ll! and l2 isashaft+l l which carriesian -agitator 16. [The agitator 7S comprisesprefre ably diametrically opposite, arc-shapedblades 18 which, are comparatively narrow radially of .the

spherical boiler M and extend in close proximity to theinner boiler suriacefiii substantially from .the bottom thereof to. a: point considerablyfabove the water level M for reasons which Willappear obvious later. .The agitator it maygfurther comprise diametrically opposite blades Mw-hichexground and firmly secured to each other by'means I of a split ring 24. The splitlring 2 3 is'clljo'seygl by.

lbolts 26 and has an internal grooveZ'l misse ;posit e ly bevelled sidewalls-23 are clamped over .ni e lled a ss iqe l e ethere l.

tend into close proximity to the inner surface 86 of the} cylindrical downward extension' iz of the boiler. The blades 78 and 84 of the agitator are preferably integralwith suitable spidersja and hubs sour which the latter are iaston the I e,%i ?it t I e "ri er end/ t" tion of the former.

I03 of a steam turbine I04 whose rotary blades I06 are mounted on the agitator shaft I4 immediately above said stationary blades. When steam is consumed, steam under pressure from the boiler I4 passes through the turbine I04'- the water and the boiler, the inner surface 80 of the latter, and, if desired, also the inner surface 85 of the downward extension 32, thereof, maybe provided with a multitude of deformations IIO which are shown, by way of example, as narrowly spaced grooves of V-shaped crosssection. These grooves III! (see also Fig. 3) may be provided by any suitable method such as rolling or cutting. In order that the grooves IIO may not interfere with the spinning motion of the water in the boiler about a vertical axis, they lie in parallel horizontal planes. Even greater efficiency may be gained, however, by forming the grooves H0 in the fashion of a screw thread which creates a torque on the agitator shaft I4 that may or may not be sufiiciently large to propel the agitator 16 at a desired speed. If the torque from the turbine I04 is sufficiently large to accomplish this, the previously described mechanical drive for the agitator shaft I4 may be dispensed with. On the other hand, the steam turbine I04 may be dispensed with and the referred mechanical drive for the agitator solely resorted to, if the drop in steam pressure occasioned by operating the turbine is undesirable. Should any condensation of steam take place in the turbine I04, the latter also effectively separates the condensed water particles from the steam and assists in the immediate re-vaporiza- This is accomplished by the rotary turbine blades I06 from which the Water particles are thrown with a centrifugal force against the boiler wall where they are either revaporized or returned to the boiler water, depending on the heat conditions.

The agitator I6 is rotated preferably at such speed that the water in the boiler spins rapidly so that its normal level 4I assumes the concave shape indicated in dot-and-dash lines at Na in Fig. 1. In this way, considerably more of the heat transfer area of the boiler I4 is contacted by the water than if the latter were not agitated, and the steam production is accordingly increased. The agitation of the water, which results in the concavity of its level, secures several other advantages which will be describedhereinafter. It is to deepen as much as possible the water trough formed by the concave deformation 4Ia. of the water level that the agitator blades 'I8 extend considerably above the normal water level 4|. I

The agitator I6 imparts to the water nearest the inner boiler surface 80, 86 a considerable centrifugal force so that said water will continuously wipe steam bubbles off the boiler wall as soon as developed and replace them with water to be transformed into steam. Hence, the steam bubbles are not permitted to cling to the boiler wall until eventually breaking away therefrom as in the case of a boiler wherein the water is static,

but they are continuously shaken off by the centrifugal force of the water while they are still of a small size. Moreover, the water swirling against the boiler wall will be under pressure which is created by the centrifugal force, and this pressure actually squeezes Y the liberated steam bubbles into the steam chamber 49 since it is the path of least resistance for them to follow.

Thus, by agitating the water as described, the steam production of the boiler per time iuiit is greatly increased over that of a boiler in which the water is static.

To increase the heat-exchange area between (Fig. 4a) with a single or multiple thread, in which case the whirling water at the boiler wall is given a slight upward surge. The natural buoyancy of the steam bubbles then cooperates with the whirling and slightly upwardly surging .water in readily removing the steam bubbles from the boiler wall where they were generated. Since the tensile strength of the boiler wall is determined bythe wall thickness from the bottom of the grooves H0 in one surface of the wall to the other surface thereof, these grooves H0 are preferably made very shallow (Fig. 3) so that very little additional thickness is required of the boiler wall over that of a wall having no grooves in it and being of the same tensile strength. To accomplish a substantial increase of the heatexchange. area between the water and the boiler,

the grooves III] need not be deep at all but may be rather shallow, in which case a greater number of the shallow grooves is provided. The heat exchange area between the products of combustion in the spiral passage and the boiler I4 may also be augmented by suitably providing on the outer surface of the latter a multitude of heat-conductive fins Hz (Fig. 4). Soda ash, sodium phosphate or their equivalent are usually added to the boiler water to inhibit scale formation'on the'boiler wall. This in addition to the brushing action of the agitated boiler water prevents even the formation of traces of scale in the grooved boiler wall over a long period of use.

The boiler I4 has been made spherical in shape a so as to require for a given internal steam pressure a wall thickness which is smaller than the "wall thickness required of a .boiler of any theboiler.

of the boiler; The agitation of the boiler water causes immediate replacement of the developed steam bubbles on the boiler wall with water particles and a squeezing of the liberated steam bubbles into the steam space above the water level, aswellas a considerably increased contact I area' between the boiler water and the heated boiler wall, resulting in a very high steam production per timeunit and per unit area of the boiler. Furthermore, the agitated water, be-

[ sides effectively preventing the formation of even traces of scale on the boiler wall, will not permit f undue priming, i. e., the well-known injection .of water particles into the steam bubbles when the latter break through the seething surface of static boiler water. Due to the spherical shape of the boiler and the agitation of the water therein, the contact area between the Water and the boiler wall is very large despite a very small Water supply in the boiler. tributes largely to a quick steam production from a cold start of the boiler. Also, since the Water supply in the boiler is so small, the steam space above the water level is correspondingly large and readily permits the equalization of internal steam pressure fluctuations so that the steam supply in said chamber may have a most uniform out-flow. The large steam chamber, which is in part defined by the concave or distorted parabolic Water level lla, affords also an ideal steam-disengaging space where the steam may gather and rid itself safely of water particles left on the surface of the steam bubbles. The grooving of the inner boiler surface greatly increases the contact area between the boiler and the water therein, resulting in a further, large increase in the steam production per unit area of the boiler. The relative thinness of the boiler wall occasioned by its spherical shape, in conjunction with the grooving of the inner boiler surface and the agitation of the boiler water, permits the transfer of a large amount of heat through the heating surfaces of the boiler per hour and results in an accordingly large capacity of the boiler.

Fig. discloses a hot water heater whose boiler construction embodies the present invention. Thus, the boiler i I it is spherical and has in its inner surface deformations Hi5 which are similar to the grooves l I i! in Figs. 1 and 3. The boiler Ii l has at its bottom a Water inlet conduit Hi. There is also provided in the boiler H4 an agitator H8 which may be the same as the agitator shown in Fig. 1. The agitator shaft I may be driven from any suitable prime mover through a non-disclosed belt connection including a pulley I23 on that end of the agitator shaft which extends beyond the hot water outlet pipe I24i. A turbine I26, similar in construction to the turbine I04 in Fig. 1, may also be provided in addition to, or in the possible absence of, the mechanical agitator drive which includes the pulley I23. The stationary blades I28 of the turbine may be mounted by bracket I36, for instance, on a horizontal partition I32 whose periphery abuts the boiler wall. The partition I32 may be secured in place by bolts I33 and nuts I34 of which the former may be conveniently welded to the boiler wall as at I35. The rotary blades I35 of the turbine are mounted on the agitator shaft I20. The grooves H5 in the inner surface of the boiler greatly increase the contact area between the hot boiler wall and. the water, resulting in a greatly increased production of hot water per unit area of the boiler. The agitation of the water in the boiler results in a considerable pressure of the water against the boiler wall, resulting in a most intimate contact between them and an accordingly thorough heat exchange.

This factor consaid outlet and having a. central opening, and a turbine having cooperating stationary and rotary blades, the stationary blades projecting into said opening and the rotary blades being carried by said shaft above said opening.

2. The combination of a vessel containing wa-.

ter and having an inner surface of revolution, means providing a passage for a heating medium in heat-exchange relation with the outer surface of said vessel, and an agitator in the vessel rotatable about the axis of said surfaceof revolution, the latter surface being provided with a multitude of shallow grooves extending circularly about the axis of rotation of said agitator.

3. The combination of a spherical vessel containing water and having a multitude of shallow circular grooves in its internal surface extending in substantially horizontal planes, respectively, means providing a passage for a heating medium in heat-exchange relation with the outer surface of said vessel, and an agitator in the vessel rotatable about a substantially vertical axis of the sphere and extending in close proximity to said internal surface.

4. In a steam generator, the combination of a spherical boiler having in its internal surfacea thread of many turns about a vertical axis, means providing a passage having a heating medium in heat-exchange relation with the outer surface of said boiler, and an agitator in the boiler rotatable about a substantially vertical axis of the sphere and extending in close proximity to said internal surface.

5. The combination of a boiler having an out let on top, a substantially vertical shaft in said boiler, an agitator in the boiler mounted on said shaft, a substantially horizontal partition in the boiler located near said outlet and having an opening, .and a turbine having cooperating stationary and rotary blades, the stationary blades projecting into said opening and the rotary blades being carried by said shaft above said opening.

6. The combination of a vessel containing Water and'having a multitude of depressions in its internal wall to increase-the heat-exchange area between the vessel and the water therein, means for heating said vessel, and a rotatable agitator in said vessel extending into close proximity to the inner surface of the latter.

7. The combinationof a vessel containing water, means for heating the wall of said vessel and a rotatable agitator in said vessel, the inner surface of said wall'being provided witha multitude of substantially parallel, shallow grooves extending transversely to the axis of rotation of said agitator.

HENRY G. SCI-IAEFER. 

